Chikuma climate — normals and trends
Chikuma (Japan) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 8.8 °C and it receives 2,511 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (21.8 °C on average) and the coldest is January (-4.0 °C). Rainfall peaks in July.
Chikuma averages 135 frost days, 3 hot days (≥ 30 °C) and 231 rainy days per year.
Chikuma has warmed by +3.0 °C between 1940 and 2025, or +0.35 °C per decade. This trend is statistically significant.
The number of frost days there went from about 153 to 117 per year over the period.
The hottest day of the period reached 33.7 °C (on 5 August 2018) and the coldest -18.4 °C (on 20 January 1942).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
ChikumaNagano
- coords
- 36.53°, 138.09°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.8°C
Average daily high
13.4°C
Average daily low
4.7°C
Annual rainfall
2,511mm
Sunshine / day
8.9h
Mean relative humidity
76%
Average peak wind
8.7km/h
Seasonal range
25.8°C
Frost days (< 0 °C)
135 d/yr
Hot days (≥ 30 °C)
3 d/yr
Rainy days (≥ 1 mm)
231 d/yr
Annual snowfall
327.4 cm
Average feels-like high
12.5 °C
Average feels-like low
2.7 °C
Average peak gust
30.7 km/h
Tropical nights (≥ 20 °C)
8 d/yr
Solar radiation
14.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.0 °C
since 1940
+0.4 °C per decade · r² = 0.67 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
33.7 °C
5 August 2018
Coldest day
-18.4 °C
20 January 1942
Wettest day
141 mm
14 August 2021
Windiest day
38.4 km/h
16 September 1961
Strongest gust
156.2 km/h
27 September 1959
Hottest feels-like
38.4 °C
15 July 2018
Coldest feels-like
-23.5 °C
20 January 1942
Snowiest day
39.7 cm
15 February 2014
Sunniest day
14.0 h
11 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 1.6 °C | +1.6 °C | 137 mm | -2 mm |
| Feb | 1.3 °C | +0.2 °C | 126 mm | -4 mm |
| Mar | 8.0 °C | +2.7 °C | 176 mm | +14 mm |
| Apr | 14.6 °C | +2.4 °C | 156 mm | -1 mm |
| May | 19.1 °C | +0.9 °C | 200 mm | +5 mm |
| Jun | 23.9 °C | +2.6 °C | 250 mm | -70 mm |
| Jul | 28.7 °C | +3.7 °C | 153 mm | -215 mm |
| Aug | 28.6 °C | +2.4 °C | 229 mm | -18 mm |
| Sep | 24.8 °C | +2.9 °C | 249 mm | -41 mm |
| Oct | 16.9 °C | +0.8 °C | 287 mm | +78 mm |
| Nov | 10.8 °C | +0.8 °C | 106 mm | -42 mm |
| Dec | 5.2 °C | +2.1 °C | 178 mm | +32 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Chikuma?
Chikuma has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 8.8 °C and it receives 2,511 mm of precipitation per year.
What is the hottest day ever recorded in Chikuma?
The hottest day measured in Chikuma between 1940 and 2025 was 5 August 2018, reaching 33.7 °C.
What is the coldest day in Chikuma?
The coldest day measured in Chikuma between 1940 and 2025 was 20 January 1942, at -18.4 °C.
Does it snow in Chikuma?
Yes. Chikuma gets on average 327.4 cm of snow per year and has around 135 frost days.
Has the climate of Chikuma warmed?
Yes: Chikuma warmed by +3.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Chikuma?
The wettest day measured in Chikuma between 1940 and 2025 was 14 August 2021, with 141 mm of rain in 24 hours.
What was the windiest day in Chikuma?
The windiest day measured in Chikuma between 1940 and 2025 was 16 September 1961, with winds reaching 38.4 km/h.
What is the warmest month in Chikuma?
The warmest month in Chikuma is August (21.8 °C on average); the coldest is January (-4.0 °C).
How much does it rain in Chikuma?
Chikuma receives on average 2,511 mm of precipitation per year, spread over about 231 rainy days.
Is it sunny in Chikuma?
Chikuma gets on average 8.9 hours of sunshine per day, roughly 3,249 hours per year over 1940-2025.
What is the biggest single-day snowfall in Chikuma?
The heaviest 24-hour snowfall measured in Chikuma between 1940 and 2025 was 15 February 2014, with 39.7 cm.
Are there tropical nights in Chikuma?
Yes: Chikuma has on average 8 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Chikuma?
In Chikuma, between 1940 and 2025, the highest apparent temperature reached 38.4 °C on 15 July 2018, and the lowest was -23.5 °C on 20 January 1942.
Compare Chikuma with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Chikuma